1. Field of the Invention
The present disclosure relates generally to remote control systems for remotely controlling electrical equipment. More particularly, this disclosure relates to a controller which receives pager signals from a pager network to control electrical/electronic equipment.
2. Description of the Related Art
Remote control systems which are capable of generating and transmitting control signals to remotely control electronic equipment are known in the prior art. Electric utility companies, for example, typically utilize a private remote control system with a private radio network to remotely control on/off switching of capacitor banks in accordance with daily electric power requirements. Such systems, however, are costly in that they require implementation and maintenance of the private radio network. In addition, their utility is generally limited to a narrow geographical region.
Hence, a need exists for a generally inexpensive remote control system which uses the public system telephone network (PSTN) to transmit control signals over a wide geographical region to remotely control electrical/electronic equipment.
The present invention relates to a remote control system in which RF pager signals transmitted by means of a wide area pager network, are received by a pager-based controller to control electrical or electronic equipment. A human operator or automated computer at a telecommunication station connected to the PSTN, initiates the transmission of RF pager signals via the pager network to the pager-based controller at the remote equipment site. In a preferred embodiment, the pager-based controller includes at least one conventional pocket pager which has been modified by having its vibrator or other indicator removed. Each time the pocket pager receives a page, it outputs a control voltage normally used to drive the vibrator. This control voltage is used to change the switching state of a relay within the controller to thereby control the on-off state of external electronics connected to the relay.
In an exemplary embodiment, two pagers are employed within the controller, each having a different pager (telecommunication) number. One pager is paged to set the relay to an ON state, while the other is paged to set the relay to an OFF state. The relay may be connected to the external electronics. As such, the external electronics can be switched into and out of operation merely by the remote operator or automated computer dialing the telecommunication number of the respective pager as allocated by the PSTN and pager network.
A pager-based controller is provided which includes at least one pager configured to receive a signal from a remote location, the at least one pager being further configured to provide an output to change an on-off state of an external electrical component; a heater unit and a fan unit to maintain a predetermined temperature range within the pager-based controller; a power supply for supplying a required AC voltage and DC voltage to electrical components within the pager-based controller; a latching relay electrically connected to the at least one pager; an interface unit electrically connected to the at least one pager and the latching relay, the interface unit configured to receive the output from the at least one pager and supply a corresponding signal to the latching relay; the latching relay including at least one normally-open contact and at least one normally-closed contact, for providing one of an open and a closed circuit to the external electrical component in response to an energization state of a coil within the latching relay; and a timing relay having a contact electrically connected in series with the output of the at least one pager to eliminate spurious signals from the at least one pager during a power-up operation.
A method of remotely controlling an electronic device is also provided which includes the steps of transmitting a first pager signal from a pager network to a pager-based controller having at least one pager therein; outputting a first control voltage from the at least one pager controller to change a switching state of a relay within the pager-based controller to thereby control an on-off state of an external electronic device which is electrically connected to the relay; and transmitting a second pager signal from the pager network to the pager-based controller at the remote site to cause a second control voltage to change the switching state of the relay within the controller to switch the on-off state of the external electronic device to a state which is opposite that which was caused by the first control voltage.
Advantageously, the use of conventional pocket pagers within the controller requires minimal set-up and maintenance costs and provides a reliable method of controlling the capacitor bank via the use of the pager network. Set-up costs are minimal since a customized private radio network for the transmission of control signals is not necessary.